The use of dual polarization in meteorological radars offers significant advantages over single polarization. Recently a standard single-polarization C-band radar was upgraded to operate in dualpolarization mode. The antenna has a 4.2m diameter parabolic reflector with a prime-focus feed. A spherical Fresnel-zone holographic technique was used to obtain the radiation pattern for the upgraded an...

Monitoring fatigue cracking of large engineering structures is a costly and time-intensive process. The authors’ present the first low-cost inkjet-printed patch antenna sensor that can passively detect crack formation, orientation and shape by means of resonant frequency shifts in the two resonant modes of the antenna. For the first time, the effect of non-linear crack shapes on the parallel an...

Computation of the broadband matching potential of a microstrip antenna requires the wideband lumped equivalent circuit of the antenna. The general topology of the equivalent circuit of rectangular microstrip patch antennas has been used to model the feedpoint impedance of microstrip antennas over a wide frequency band and equivalent circuit parameters are determined using optimization techniqu...

Microwave sensors are robust non-contact measurement devices for industrial and vehicular application. Phased array-antenna modules, located in the front-end of the sensor, are often used to enhance the performance of this device. In this paper, a novel 24-GHz microstrip linear array antenna with beam-scanning and signal-amplification properties are presented. The phase shift section is designe...

A novel UHF RFID tag antenna that can be seamlessly integrated into wrapping paper of metallic objects is reported. When designed for printing on cigarette carton with aluminum foil contained, both numerical simulation and measurement indicate that the proposed antenna has input impedance of (20 + j149) at resonant frequency of 915MHz, which provides satisfactory conjugate match to the Alien Hi...

This paper summarizes our recent research efforts to realize efficient electrically small antenna (EESA) systems based on ideal analytical and numerical metamaterial-based antenna systems, and physically realized metamaterial-inspired antenna designs. Our theoretical and numerical studies of the radiation and resonance behaviors of the proposed metamaterial-based EESA systems, as well as our ef...

Abstract—A key feature of upcoming 4G wireless communication systems is multiple-input-multiple-output (MIMO) technology. To make the best use of MIMO, the antenna correlation between adjacent antennas should be low (< 0.5). In this context, we propose a correlation reduction technique suitable for closely spaced antennas (distance, d < λ/40). This technique reduces mutual coupling between ante...

In this paper, we propose low-loss and broadband terahertz (THz) waveguide-to-coupled microstrip transitions using dipole antenna with directors. The simulation and measurement show that insertion/return loss and bandwidth of the waveguide transition can be improved by adding two directors to the basic dipole antenna. The fabricated transition with two directors on a 50 μm-thick quartz substrat...

The space surrounding a radiating or scattering object is often divided into three regions, namely reactive near-field, near-field (NF) or Fresnel region and far-field (FF) or Fraunhoffer zones. In addition, the term “very-near-field" region is sometimes defined as very close to the antenna (e.g., antenna aperture). There are no abrupt boundaries between these three zones, however there are som...

A new meta-surface structure (MSS) with a near-zero refractive index (NZRI) is proposed to enhance the performance of a square loop antenna array. The main challenge to improve the antenna performance is increment of the overall antenna volume that is mitigated by assimilating the planar NZRI MSS at the back of the antenna structure. The proposed NZRI MSS-loaded CPW-fed (Co-Planar Waveguide) fo...